Method for manufacturing concrete pipes



Jan. 13, 1931. A. HORTEN METHOD FOR MANUFACTURING CONCRETE PIPES Original F'iledl Feb. 23, 1925 dia-meter of which corresponds to the inner `dia iet'er of theusu'alenlarged portion of the pipes of this type used for making the medium in the joint.

pipe joint. Therefore, the radius of the/enlarged portion a of the core exceedsthe radius of the adjacent portionofthe body a of thepipe by the thickness of the Wall of 'the complete concrete pipe plus thespacere-V quired for vapplying the ordinary packing stood that also the portion a tapers slightly from therbottom end'tovvardsthe body a,

andthat the body a of thencore .slightly tapers from the bottom end to the top end thereof as shown in Fig. l, the object of thus tapering the core being to facilitate the removing of the core from the concrete pipe, as Will be described hereinafter. i

The corea, a is made from strong andsmootli material having high conductivity for heat. Preferably kitv consists of a suitable vmetal such as cast iron.. But in some vcases I place protective'sheets '00, c of metal or other suitable material on the saidlayers ofjrubber. Preferably Washers cando 'of'v Vrubber are placed between theend faces "of the core CZ, a and the lids Z), o. l

VSuitable means areprovidedfor rigidly connecting Ythe lids and Zi tothe core c,

chain of 'a hoisting machine.

.ap As show-n in Fig. la rod "w is provided I for this purpose. gThe lid c is'formed at its bottom face with' an axial cylindrical Y lug izladaptedv for engagement `with a cor responding' socket made in the4 rotary table, and-'the rod in is formed aft-its top .end With aneye g' forsuspendingvthe same from the y if. Through theupper lidY pipes c and 1,

1are"'passed, through. Whicli'a suitable hea-t1 ing orV cooling medium .may bek circulated through.thefinner'part of the core, and -in some-cases Ipro'videa vent for removing the air'Y from the core.l The iowerlid fh is formed with a discharger opening'fnor- Y mally .closed by a valve` l, the stem.lfbeinjg passed? upwardly through" the core and carrying 'at itsouter end a nut lfforpress ing the valveion its seat.V At their outer sides-the lids'b and-bf are provided With annular-recesses b3, b* having -rings [ande fitted therein The outer ldiameters of thev saidrings' are YKequal'respec- YVtivelyl tio-.fthe outer diameter of the concrete i pipe and the enlargedportion thereof, and vithey;embrace respectively with theiry top and bottoni parts thejtop and bottomparts It Vwill VbeV under-4 larms are used'for each ring d and e.

ofthe core a, a. Thus the outer portions of the said rings determine the thickness of the concrete pipe R and the position of the endfaces of the said pipes. The rings d and c' are connected withthe lids ZJ and 5' so rthatthey may be readily removed therefrom. 'fo-show what may be done arms f are `rockiiigly mounted on the lids, which arms are adapted to be turned outwardly for fixing the-rings to' the'lids. In Fig. l onlyone of the said .arms isshoivn. But I Wish it to be understood that at least three v lVhen turning the saidarms .inwardly the rings d and c can be readily removed.

After constructing the core'in the manner described 'I place the vsame in vertical position `on the rotary table and impartslow rotary movement thereto While gradually applyingfthe soft concrete thereto. Apparatus suitable for thisY purpose has been described in my prior Patent 1,523,539, and I deem itnot necessary to describe the appara-tus` in detail. The core may, be

-.placed on the said table While beingatzroom temperature. But I prefer slightly to heat the same, for example by shortly immersing the Vsame into WarmV Water, or filling the saine .Y with Warm Water. After' the first part ofthe concrete has been applied `the Vcore is. perfectly insulated as against `loss w se of heat, therlids beingV coated with insulating material in the "manner described, and. the

vrconcrete applied to the core a, a having low conductivity for heat.v The mass of conciete"vvhich .is comparatively cold, is uniformly and slightly heated from the core.

l VAfter moulding the inner layer. ofcon- `crete Vhaving 'a thickness of oneghalf the thickness of the desired'wall of thev pipe i tliexsaidf iayer of'con'crete` is allo'vvedto set andlinr order that theY period of time required for setting be reduced 'I carry the core and the inner layerY ofV concrete applied Y thereto into .the apparatus shoWnin Figs.

4 and 5, a suitable hoisting machine consisting-of a VcraneK Yrunning onl asuitabie .rail Gbeing `provided for this purpose; As shown thesaidapparatusconsists of a pit vcomprising a large chamber A -lled with i hot Water and a plurality of small vchambers B. .The Watercontained in the chamber A is heated for example by meansjofa heating coil- H to a temperature of'from 40 to160 C. :The sizeof ,the chambers 'Bl is comparativelyl small and it lis not flarger'than Y is necessary forreceiving the core a, la and the concrete applied thereto. The chambers are heatedby the heat Ytransmitted thereto vfrom thelcha'mber A...

After a; pipe and coreehave been Vplacedintooneof the chambersB 'the lidF closed: The small amount'of air Within the saidw chamber is rapidly saturated with .vaporizedpwaten and Yby reason. of the elefio,

Y mesme vated temperature the concrete begins to set after a short period of time. In this process only a very` small amount of vthe Water of the concrete is vaporizved, so that'no f:

cracks are producedV in the layer ofconcrete'. After aV short period of time the :con-

i creteV -hasset so far that it may be exposed to contact With Warm Water. Therefore,

4after removing the lid F` thecoreiis' again elevated kby the hoisting apparatus I'and. carried into the hot lyvater contained within I 'thejchamber AQ WithinY the said Water setting is completedv Within three or four hours'.

'llhcreaftei',l the core andthe set 'layer of concreteare carried tok theflmging appara-L tus,"where the second layer is applied to the innerv layer in the same Way Vas has Vvbeen described above.

If it is desired to manuv facture re-inforced concrete pipes I apply the re-inforcing iron tothe set inner layerVv ypriorto applying the outer layerA thereto,V the said reinforcing iron being in the formr ,of a net,a helically'wonnd Wire or strip iron. 1

Ink Fig.' G I'have shown the core, the VVinnerl and outer layers and there-inforcing iron' .on av larger scale, fajbeing the core, Rf? the inner layer of concrete, E the helically Wound strip iron, and, R theoiiter vlayer of concrete.A In the saidligure I have shown a very thin layer of concrete-R which `.is

rst applied to the set inner layer R0 before applying the stripiion E thereto, so that the said strip iron is Wound into the said soft concrete and intimately connected with the said concrete. After applying the outer v flayer of concrete, Vthe outer surface-0f the pipe indicatedin Fig. v1` by the pointed, 0,

` Vscribe the' same Vin detail.

p, g, maybe moulded by removing the excess f of v.material by cutting Wires while gradually ',rotating'the core. f This method is know in the ,art Vand I deem' it rnot necessary to Now the core is again carried to the pit e B,Where the vouter layer is made to set-in the manner described above. Finally the core is removed 'from' the pipe R.

AfterV the core and the pipe carriedithere'- byfha've been removed'fromthe pit Athe rings rdlo-jand @are removed v:from the lids'V b "and b andthe core'and massof AconcreteR` are placed with the4 bottom on. the ring r asv shown inFigfQ, so that the Whole massv of the V"coreand pipe bears on the lower. end.

face of the enlarged bottom part ofthe pipe.

' In order that .the core fbe .more readilyl placed on the said'ring I prefer to form the Nowfthe hot lid with a "bevelled, margin ye.

Water Which'gmaylbe containedwithin 'the vhollow-of fthe coreis discharged through the Valvey 1,andfa cooling medium, such` as cold .water is.'inadegtocirculatefthrough the said core. 'Ivherebyth'e core 21,0V isslightly contracted While the concrete pipe VIt remains f at elevated temperature by reason ofits low E conductivity for heat, so that it is not con ordinari ',trate There `fr,

eral :the sere iS `leerla lense 1,11 12e ialldlretlonbut also. 1n axial reason" theisbouldelt-1510ijmV y' ,theScore tlrelbody0b` iscontracted downward-N Y reis( contractedot only meters, thereis an appreciable longitiidinal'- displacementof thecorea relatively'toitherl' therxpipe lf l1ave..ff01d thatfff Y KA,if-*thecoles automatically discern" elected. ilfroiiiithe fpipe,V and that a Slight-blow lilaihammer dSuiie'ntto remove the cere from the pipe rWitlfl.out injuring the lla-ttes` verder that the" core ble morevv R which *as'sist's 1in disconnecting *the made.

readilyiseparated from the-pipe I 4piroir-idleZ the same With a very `s1n oo tlisurface;and somezcasesapply thereto., suitablebine- ,duim ,suchas oil, graphite or the `like prior Y e5 e, anplyme ltliefiinner' vlayer yof.eoncretetgivill'beunderstoodfthatin the manufac f ture; of athe' :Pipes .eachzcor'e .is vsli'sed'v,'several heursifor making, av single :pipef 'Iherefore,' 90' Y ivlienrfusingfcores, imade :from metal .thecost of thefstocl` of [cores is very -high-. 2-.V In order to reduce'theicostl `prefer tomanufactnre L the coresfromj concretehaving ai. .high-cQn-. v

`` diictiivty,:for heat, soLthatfonlyatheflids Z2, b, 95

and thel rings d, e are made-fr0m-metal. ,Inv

tliepraotice' dfthisipart of my invention I manufacture a vtubular mouldvfrom any suit* ablev `material, the inner configuration of which exactlycorresponds to the inner form of ,the concrete pipeiR and Iplace a core of metal or .Woo-d into the said pipe, whichk 1 corresponds to 4the inner diameterof the coreA a, a. Themould thus formed is iilled with f v vto, and I yallow the said` concrete ltoset in 'y theordinary Way. n The concrete pipe @,a g

concrete havingmetal chips admixed there-Y vvhich ,hasv thus beenmanufactured is used.

concrete corea, axbe injured after some time of'useit may befreplaced at loW cost, While usedforanylength oftime. v

Y :The separation of the core fromthe con- Y crete pipe' may bel further accelerated'rby exinthe manner described above. Shouldthe e Y ilo 'arenas e; e @Heather man parts maybe ternally heating thepipe R While internally cooling the core. For veXafinple,I place-,the

coreandpipe on the ringfvvithin a 'pit simiitis noti` necessary, tov carry. the core from the chamber'rBfinto the-chamber A.k f`Apparat tusforcarrying'o-utthisimodication of my r j Y. 312;; Y." y .l

method Vv vill reaxlilyV .suggest 4,themselvesy to those skilled inthe art, and I Vdeem it not Y necessary to show the same in the drawings.

v tcu-lar method j herein; V-

While in describing the invention reference has been madeto particular examples i embodying the .same I wish'it tobe understood that I dob not limit myself to the parl] VvIclaim:v l'

- fio v1.*'lhe herein described method of -ma'nufacturing pipes which consistsinfapplying V- i plastic matter containing cement to alcore,V allowing theV said plastic matterl partly to l set atl elevated temperature within an air chamberof limited volume, contlnulng setting-within hotwater, and thereafterf cool-v e ing the core while continuing heatingofthe Y set plastic matter.

' V`,2. The herein described method of manufacturing pipes, which consists in heating Y Ia taperingfhollow 'co-re formed atthe end of larger diameter with an enlarged portion, l applying'plastic matter containing 'cement to the saidV core, allowing the plastic matter Y K tosetat elevated temperature at rst withf in air and thereafter'within hot water, and

circulating a lcooling medium lthrough the f I said core while continuing heating of the set plastic matter.

' ALPHoNs IJLRTEN.l

:LSU 1 p and the vapparatus describedv In testimonyw whereof VI have affixed my 

